In:
International Journal of Systematic and Evolutionary Microbiology, Microbiology Society, Vol. 55, No. 6 ( 2005-11-01), p. 2543-2549
Abstract:
A polyphasic study was carried out to determine the taxonomic position of two aerobic, cyanide-degrading bacterial strains, designated L61 T and L22, which had been isolated from a bioreactor for the treatment of nickel-complexed cyanide. The two isolates exhibited almost identical taxonomic characteristics. Phylogenetic analysis inferred from comparative 16S rRNA gene sequences indicated that the isolates fall in a sublineage of the genus Rhizobium comprising the type strains of Rhizobium giardinii , Rhizobium radiobacter , Rhizobium rubi , Rhizobium larrymoorei , Rhizobium vitis , Rhizobium undicola , Rhizobium loessense , Rhizobium galegae and Rhizobium huautlense . Cells of the two isolates are Gram-negative, aerobic, motile and non-spore-forming rods (0·6–0·7×1·1–1·3 μm), with peritrichous flagella. The DNA G+C content is 60·1–60·9 mol%. Cellular fatty acids are C 16 : 0 (2·2–3·3 %), C 18 : 0 (2·1–3·2 %), C 19 : 0 cyclo ω 8 c (9·9–16·8 %), C 20 : 3 ω 6,9,12 c (2·7–3·3 %), summed feature 3 (7·2–7·7 %) and summed feature 7 (67·8–73·7 %). The strains formed nodules on a legume plant, Medicago sativa . A nifH gene encoding denitrogenase reductase, the key component of the nitrogenase enzyme complex, was detected in L61 T by PCR amplification by using a nifH -specific primer system. Strains L61 T and L22 were distinguished from the type strains of recognized Rhizobium species in the same sublineage based on low DNA–DNA hybridization values (2–4 %) and/or a 16S rRNA gene sequence similarity value of less than 96 %. Moreover, some phenotypic properties with respect to substrate utilization as a carbon or nitrogen source, antibiotic resistance and growth conditions could be used to discriminate L61 T and L22 from Rhizobium species in the same sublineage. Based on the results obtained in this study, L61 T and L22 are considered to be representatives of a novel species of Rhizobium , for which the name Rhizobium daejeonense sp. nov. is proposed. The type strain is L61 T (=KCTC 12121 T =IAM 15042 T =CCBAU 10050 T ).
Type of Medium:
Online Resource
ISSN:
1466-5026
,
1466-5034
DOI:
10.1099/ijs.0.63667-0
Language:
English
Publisher:
Microbiology Society
Publication Date:
2005
detail.hit.zdb_id:
215062-1
detail.hit.zdb_id:
2056611-6
SSG:
12
